Dogelog Player is a Prolog system that is 100% written
in Prolog itself. It is avsailable for the JavaScript,
Python and Java platform. We show how the stable
ordering of Prolog variables in Dogelog Player allows
highly efficient constraint solving approaches.

We convert the undirected graph into a directed graph
and create adjacency lists. This inequality graph doesn’t
have the same delayed evaluation overhead than
(#=)/2 and dif/2. We demonstrate map coloring and
sudoku solving. Further improvements in a
subsequent article.

See also:

Map Coloring and Sudoku Solving
https://twitter.com/dogelogch/status/1766885890712883276

Map Coloring and Sudoku Solving
https://www.facebook.com/groups/dogelog

Mild Shock schrieb:
> Dear All,
>
> We are happy to announce a new edition
> of the Dogelog player:
>
> - Enhanced '$YIELD'/1:
>   Previously the '$YIELD'/1 instruction was hard coded
> to understand an integer for sleep/1 and an atom for
> native library loading. The implementation has been
> change to accept a Promise object, known from
> JavaScript. Emulations were made available for
> Java and Python.
>
> - Async I/O:
>   Based on the new '$YIELD'/1 and a buffer fast path
> idea, the console reading, file property and file
> reading have been asyncified. There is no change in
> the Prolog API, files are still to be opened via the
> ISO core open/3 and accessed via ISO core get_code/2
> respectively ISO core peek_code/2. But input can now
> be executed quasi-parallel by multiple tasks.
>
> - HTTP client:
>   The ISO core open/4 has been moved to the library(spin).
> The support of the HTTP and HTTPS protocol in open/3
> and open/4, has been extended from the JavaScript
> browser to the JavaScript command line (by means of
> new fetch in nodejs >21). Further supported targets
> are now Python and Java (by means of new HTTP client
> in JDK >21).
>
> Have Fun!
>
> Jan Burse, http://www.xlog.ch/ , 07.03.2024

Small implementation node about the new HTTP client
in Dogelog Player for JavaScript. I am using fetch()
everywhere. No need to get help from libraries such as:

> Axios is a promise-based HTTP Client for node.js
> and the browser. It is isomorphic (= it can run in
> the browser and nodejs with the same codebase).
> On the server-side it uses the native node.js http
> module, while on the client (browser) it uses XMLHttpRequests.
https://axios-http.com/docs/intro

First of all XMLHttpRequests is deprecated in the
browser, use fetch() instead. And nodejs has fetch()
since release 21.x.x as well. So they have become
isomorphic making AXIOS obsolete:

> Notable Changes - Oct 17, 2023
> The recent update to Node.js, version 21, includes
> an important change to the fetch module as well as
> WebStreams . Both modules were marked as stable
> after a recent update.
https://nodejs.org/en/blog/announcements/v21-release-announce

Mild Shock schrieb:
>
> Dogelog Player is a Prolog system that is 100% written
> in Prolog itself. It is avsailable for the JavaScript,
> Python and Java platform. We show how the stable
> ordering of Prolog variables in Dogelog Player allows
> highly efficient constraint solving approaches.
>
> We convert the undirected graph into a directed graph
> and create adjacency lists. This inequality graph doesn’t
> have the same delayed evaluation overhead than
> (#=)/2 and dif/2. We demonstrate map coloring and
> sudoku solving. Further improvements in a
> subsequent article.
>
> See also:
>
> Map Coloring and Sudoku Solving
> https://twitter.com/dogelogch/status/1766885890712883276
>
> Map Coloring and Sudoku Solving
> https://www.facebook.com/groups/dogelog
>
> Mild Shock schrieb:
>> Dear All,
>>
>> We are happy to announce a new edition
>> of the Dogelog player:
>>
>> - Enhanced '$YIELD'/1:
>>    Previously the '$YIELD'/1 instruction was hard coded
>> to understand an integer for sleep/1 and an atom for
>> native library loading. The implementation has been
>> change to accept a Promise object, known from
>> JavaScript. Emulations were made available for
>> Java and Python.
>>
>> - Async I/O:
>>    Based on the new '$YIELD'/1 and a buffer fast path
>> idea, the console reading, file property and file
>> reading have been asyncified. There is no change in
>> the Prolog API, files are still to be opened via the
>> ISO core open/3 and accessed via ISO core get_code/2
>> respectively ISO core peek_code/2. But input can now
>> be executed quasi-parallel by multiple tasks.
>>
>> - HTTP client:
>>    The ISO core open/4 has been moved to the library(spin).
>> The support of the HTTP and HTTPS protocol in open/3
>> and open/4, has been extended from the JavaScript
>> browser to the JavaScript command line (by means of
>> new fetch in nodejs >21). Further supported targets
>> are now Python and Java (by means of new HTTP client
>> in JDK >21).
>>
>> Have Fun!
>>
>> Jan Burse, http://www.xlog.ch/ , 07.03.2024
>

In 1997, Hong Kong judge Wayne Gould saw a partly
completed puzzle in a Japanese bookshop. Over six years,
he developed a computer program to produce unique
puzzles rapidly. The program tries to keep one puzzle
ahead of you, by generating the next puzzle while you
are solving the present one.

In the following we show a Prolog program, where
the random generation of a Puzzle is performed in
less than 2 seconds. The Prolog program was mainly
developed for Dogelog Player. We could test the
Prolog program also with Prolog systems such as
SWI-Prolog, Scryer Prolog and Trealla Prolog.

The smallest domain first variable ordering heuristic
allowed us to solve some hard problems below a minute.
Turning the heuristic into a static ordering before
search gave us a further boost and the baseline for
randomization. Measurement showed that solving blank
Sudokus doesn't have a large time variation.

See also:

Birthday Paradox and Sudoku Generation
https://twitter.com/dogelogch/status/1767714755827908991

Birthday Paradox and Sudoku Generation
https://www.facebook.com/groups/dogelog